Densha otoko (2005)

Tsuyoshi Yamada is a dyed-in-the-wool otaku--an obsessive fan and collector of anime, comics, figures, and the like. He's also terribly shy and awkward around women. One evening, while riding a train home, he sees a woman named Saori being harassed by a drunken passenger and decides to intervene. Saori sends a set of expensive tea cups to Yamada as a token of gratitude. Seeking further advice, Yamada turns to the users of an online message board, who help him to clean up his nerdy image and ask Saori out. As Yamada tries to win over the girl of his dreams, he must fend off a pushy co-worker, a rival suitor, and the temptation to slip back into his old habits.